Indeed, but I haven't been bothered to edit the rest of the series as Kiriraitaa works are really hard to clean... translations are available on the original japanese series, though.
The whole family are worthless retards; the sister for being incapable and spoilt, the mother for being fucktarded over a shiny unique accessory. Big sis's behaviour, is understandable and logical with in context (not saying it's right, of course). Of all of them, the mother is the most worthless piece of shit for being too obsessed over that shell, neglecting the other child and then being unable to realise what she's done.
1.) The shell cannot be taken off, at least by the koyukkuri, since it lacks the strength too. While it did seem to come off, it snapped back into place and hair_accessories are never removed by Yukkuris, so in this event instinct screwed it over since all it knows, as a koyukkuri, is to keep its accesories.
2.) The mother thought she was giving both equal care, as evidenced by the Patchouli, and she did make attempts to (giving both equal bedding). The only care she showed was to help the shell_marisa get to where she can't go, since it lacked the strength too. We don't know how old it is or if it was planning on being taught once it was older. Whats odd is that it seems yukkuri tend to kill mutants as they grow older, and while the Reimu was biting it, it seemed more like play and the Patchy did tell it to stop.
3.) While it is understandable that a sibling feels jealousy when a new child comes along, especially one that is special and requires special needs, it is excessive that it went all apeshit and tried to murder it. Patchy was simply reminding Marisa, although it didn't go into enough detail, that Marisa was giving one too much attention. There is no sign that both weren't given the same food, bedding, and at least to the Marisa, love.
4.) It is incapable because of the size of the shell, and koyukkuris are weaker in general since this one is newly borned.
To me, the older-sister overreacted and killed the sister without justification when looking at it from our point of view, and the mother is careless in some respects, but I can chalk that up to poor instinct or inexperience as a parent.
anelaidlives, none of this is what you think it is
From what it seems like, you'll just have to disagree. Sure, it's incapable; but it doesn't even try to do anything (firstly demanding that others do it, and then only struggling after that), nor show any real concern for the treatment of its sister. As for "no sign" that both weren't given equal "love", it seems obvious that it's hammered in at post #14728 and she only "thought" she was giving equal care, a passing-thought while obsessed with Shell.
Nevertheless, it's obvious it's due to different interpretation. Nobody is going to be changing their view, so it would be best to avoid another pagefiller.
Also it demands because thats all a koyukkuri can do, and there isn't any clear evidence it doesn't care for its sister that I can see.
She wasn't obsessed either, but do you agree that taking off the shell, at least, would be something out of the question given, at least what I understand of, yukkuri psychology.
I didn't overlook anything. If you look at the examples, the only time it reacts badly is on the collage where it's shown to be neglected (before that, it's the mother reacting badly to anything that the other Marisa does that might remotely endanger Shell). Sure, Shell needs help, except it was given so much 'help' that the other child as neglected. Not surprising that the other one would see it as favouritism and that Shell was a threat. If the other Marisa was involved in all the activities, then that would have been avoided as both yukkuris would still have gotten what they needed, in treatment and care.
Of course, expecting that from a yukkuri is too much. Yukkuris being yukkuris, and delicious suffering caused by their stupidity.
Well in my honest opinion, the only truly "innocent" one was Shell herself, the mother is clearly at fault and the sister, while facing some negligence because of the mother, was too cruel and went too far because of jealousy + the negligence of the mother.
Shell many times wanted her sister on their activities, but her mother would overeact at the slightlest "potentially dangerous act" from the normal sister and many times just picked Shell alone instead of both.
So i don't agree about Shell being a brat, specially because the closest thing as demands we saw were, exactly when her sister started to give her the cold shoulder and even troll her on purpose, so it's pretty much understable, before that? she just wanted her sister to have fun with her too.